There is provided a balancer device for an internal combustion engine that suppresses lubricating oil from failing onto a reduction gear and a pump drive gear provided to drive and rotate an oil pump and thereby suppresses an increase in resistance against rotation between the reduction gear and the pump drive gear. The balancer device for the internal combustion engine includes a lower side housing on which a balancer drive gear, a first balancer shaft including a first balance weight, a first gear, a second gear, a second balancer shaft including a second balance weight, and the reduction gear are mounted. The balancer device also includes an upper side housing formed in such a shape that covers the balancer drive gear, the first balancer shaft including the first balance weight, the first gear, the second gear, the second balancer shaft including the second balance weight, the reduction gear, and the pump drive gear from above in the state that the oil pump is assembled with the upper side housing such that the pump drive gear is meshed with the reduction gear. The upper side housing is assembled with the lower side housing. The balancer device further includes an exposure opening formed in the upper side housing such that only the balancer drive gear is exposed from the upper side housing to be meshed with an engine-side gear.

A balancer structure for an internal combustion engine and the internal combustion engine are provided. A transmission driving gear are arranged to be rotatable integrally with a crankshaft. A transmission driven gear is arranged to be rotatable integrally with a first balance shaft. The transmission driven gear meshes with the transmission driving gear. A balancer driving gear is arranged to be rotatable integrally with the first balance shaft. A balancer driven gear is arranged to be rotatable integrally with the second balance shaft. The balancer driven gear meshes with the balancer driving gear. The first balance shaft includes an output portion. The output portion outputs torque to an engine-driven accessory.

A balance shaft structure includes a balance shaft including a balance weight, a driven gear to rotate the balance shaft by being engaged with a drive gear, a scissors mechanism, whose position in an axial direction is regulated, including a scissors gear to reduce backlash between the drive gear and the driven gear and an axially urging member to urge the scissors gear toward the driven gear in the axial direction, a first regulating portion to regulate an axially inner position of the scissors mechanism, and a second regulating portion fixed to the balance shaft on a side close to the shaft end part of the balance shaft beyond the first regulating portion and configured to regulate an axially outer position of the scissors mechanism.

A powertrain includes a housing and a crankshaft-balancing assembly that is at least partially disposed inside the housing. The crankshaft-balancing assembly includes a crankshaft rotatable about a longitudinal axis. The crankshaft-balancing assembly further includes a drive member secured to the crankshaft. The crankshaft-balancing assembly also includes a first shaft rotatable about a first pivot axis. The first shaft is rotatable in response to rotation of the crankshaft. The crankshaft-balancing assembly includes a weight member that extends from the first shaft. The weight member is positioned along the first shaft to balance the crankshaft during rotation of the crankshaft and the first shaft. The crankshaft-balancing assembly also includes a drive member that surrounds the first shaft and a portion of the weight member. The drive member of the first shaft defines a void that opposes the portion of the weight member.

A vibration reduction device (5) including: a counterweight (6) provided to a crankshaft (14) of a Stirling engine (1); and an electric balancer (7) being attached to a crankcase (15) and including a balance weight (73) rotated by an electric motor (74). An inertial force of the counterweight (6) is set to approximately a half of a combined inertial force of pistons (12, 13). Inertial force of balance weightL2=combined inertial force of pistonsL1 is satisfied when a mass of the balance weight is set, where L1 denotes a distance between a vibration reduction target position and a rotation center (O1) of the crankshaft (14), and L2 denotes a distance between the vibration reduction target position and a rotation center (O2) of the balance weight (73).

Provided is a balancer device in which friction loss between a driving shaft and a bearing can be reduced. The balancer device of the invention comprises an upper housing and a lower housing. The upper housing receives the upper half portion of a rolling bearing which rotatably supports the driving shaft. The balancer device includes a first member which biases the rolling bearing toward a bearing receiving portion.

A machine having a reciprocating slider crank mechanism, wherein an axis of a crankshaft, an axis of a first balancer shaft and an axis of a second balancer shaft are not arranged on the same plane, wherein vibration is highly controlled. The machine includes the reciprocating slider crank mechanism configured so as to satisfy setting formulae below:
U.sub.Cr=U.sub.P0.5
.sub.Cr=180
U.sub.B(Fr)={U1.sub.B(Fr).sup.++U2.sub.B(Fr).sup.2}.sup.1/2
U1.sub.B(Fr)=U.sub.P0.5{Lx.sub.B(Rr)/(Lx.sub.B(Rr)Lx.sub.B(Fr))}
U2.sub.B(Fr)=U.sub.P0.5{Ly.sub.B/(Lx.sub.B(Rr)Lx.sub.B(Fr))}
.sub.B(Fr)=180arctan(U2.sub.B(Fr)/U1.sub.B(Fr))
U.sub.B(Rr)={U1.sub.B(Rr).sup.2+U2.sub.B(Rr).sup.2}.sup.1/2
U1.sub.B(Rr)=U.sub.P0.5{Lx.sub.B(Fr)/(Lx.sub.B(Fr)Lx.sub.B(Rr))}
U2.sub.B(Rr)=U2.sub.B(Fr)
.sub.B(Rr)=180arctan(U2.sub.B(Rr)/U1.sub.B(Rr)).

A balancer device for an internal combustion engine is provided, wherein the drive mechanism 8 and the oil pump 3 are arranged on the side opposite to driven balancer weight 135 in the axial direction of the driven balancer shaft 5.

There is provided a balancer device of an engine. The balancer device is configured to reduce rotation vibrations of the engine. A crankshaft is disposed on a mating surface of a crank case divided into an upper case and a lower case. A balancer shaft is disposed below the crankshaft. A balancer housing accommodates therein the balancer shaft. The balancer shaft is disposed on a mating surface between the lower case and the balancer housing.

A balance assembly for an engine is provided. The balance assembly includes a first electric motor coupled to the engine and configured to rotate a first eccentric mass relative to the engine, the first eccentric mass being coupled to a first shaft of the first electric motor, and a second electric motor coupled to the engine and configured to rotate a second eccentric mass relative to the engine, the second eccentric mass being coupled to a second shaft of the second electric motor. The first and second electric motors are configured to rotate the first and second eccentric masses in order to balance a vibration characteristic of the engine.